Transcriptome of the plant parasitic nematode Meloidogyne graminicola during interaction with rice plants. AYR

Root-knot nematodes (Meloidogyne species) are microscopic soil worms that infect plant root systems and cause large economic losses to cultivated plants. They induce the differentiation of root cells to establish a feeding site that enable the parasites to pump large amounts of nutrients from the plant. The root-knot nematode Meloidogyne graminicola is a major pest of rice (Oryza sativa L.) in Asia and in Central America. Severe infections result in a stunted root system preventing the development of the rice plant. In the O. sativa Nipponbare susceptible cultivar, M. graminicola completes its life cycle in 3 weeks (Nguyen et al., Rice Rice 2014, 7:23). Resistance to M. graminicola has been recorded in the rice African related species Oryza glaberrima, specially in the O. glaberrima accession TOG5681 used in this study. The aim of this transcriptomic project was to decipher nematode gene expression patterns during its life cycle in the Oryza species and to provide insights on the pathogenicity mechanisms. Dual RNA-seq, that is the simultaneous sequencing of two organisms, was performed on M. graminicola-infected rice plants and a de-novo transcriptome covering the pre-parasitic and parasitic M. graminicola stages was established. A bioinformatic approach combining development of a "secreted protein prediction" pipeline to expression profiling has been used to identify novel effectors. These data also provided insights on M. graminicola genes that are differentially expressed across the M. graminicola life cycle in rice plants.